The present invention relates to a torque measuring apparatus. More particularly, it relates to an apparatus which is installed between a power source such as an electric motor or an internal combustion engine and a load to be driven by the power source and which measures the torque transmitted from the power source to the load.
An electromagnetic powder clutch transmits a torque by utilizing the magnetic coupling force of electromagnetic powder which develops when the electromagnetic power obtained by finely pulverizing a magnetic material is magnetized. It has heretofore been known that the transmission torque capacity of the electromagnetic powder clutch is substantially proportional to an exciting current flowing through an exciting coil of the clutch, without appreciable regard to the difference between the revolutions of the input and output sides of the electromagnetic powder clutch, i.e., the slip revolution number of the electromagnetic powder clutch.